1. Field of the Disclosure
The present disclosure relates to systems and methods for using optical coherence tomography (OCT) to image both the vitreous and the retina in the eye. The image of both tissues may be created sequentially, simultaneously or near-simultaneously from at least one OCT image.
2. Background of the Invention
Vitreous body is a transparent gel-like structure in the posterior of the human eye. It provides certain physiological functions to protect the normal human vision, including enabling a metabolic conduit for the lens and removing cells and large macromolecules from the vitreous cavity to maintain its transparency. However, due to aging or pathological processes, disruptions of the gel structure of the vitreous can cause a number of blinding conditions, such as rhegmatogenous retinal detachment, diabetic retinopathy and macular hole. Therefore, visualization of the transparent vitreous and monitoring its changes can be of great interest to the early clinical diagnosis of these pathologies.
For many vitreoretinal diseases, surgical treatment is the only option. During the vitreoretinal surgery, complete and safe vitrectomy is one of the key steps to achieve optimum outcomes. As a result, detection of the residual vitreous and visualizing the vitreous retina interactions during vitrectomy can substantially improve the outcome of current vitreoretinal surgeries.
Due to the transparent nature of the vitreous, direct optical imaging is challenging. Ultrasonography has been used to image the vitreous. However, the resolution and contrast is low and it requires coupling gel, rendering it unsuitable for surgical applications. Optical coherence tomography (OCT) is a high resolution, non-contact and highly sensitive imaging modality which has become the standard in diagnostic ophthalmology. It has been demonstrated that OCT can image the vitreoretinal interface once the vitreous is detached from retina. However, due to the extremely low back scattering, the vitreous body is difficult to image.
Recently, a research group at MIT proposed a technique named enhanced vitreal imaging by adjusting the threshold and contrast of the OCT image to enable visualization of vitreous. However, in the MIT proposed technique the retina image below the vitreous is completely saturated rendering the image overall less useful in surgery.